FIG. 1 depicts an air-bearing surface (ABS) view of a conventional read transducer 10. The conventional read transducer 10 includes shields 12 and 20, sensor 14, magnetic bias structures 16 and conventional electric gaps 22. The read sensor 14 is typically a giant magnetoresistive (GMR) sensor or tunneling magnetoresistive (TMR) sensor. The read sensor 14 includes an antiferromagnetic (AFM) layer, a pinned layer, a nonmagnetic spacer layer, and a free layer. Also shown is a capping layer. In addition, seed layer(s) may be used. The free layer has a magnetization sensitive to an external magnetic field. Thus, the free layer functions as a sensor layer for the magnetoresistive sensor 14. The magnetic bias structures 16 may be hard bias structures or soft bias structures. These magnetic bias structures are used to magnetically bias the sensor layer of the sensor 14.
The electric gaps 22 are used to electrically isolate the read sensor 14. Typically, the conventional electric gaps are formed after the read sensor 14 and magnetic bias structure have been formed and the conventional transducer 10 has been planarized. After the chemical mechanical planarization (CMP) or analogous planarization step, the conventional electric gaps 22 are formed. The shield 20 may then be deposited.
Although the conventional magnetic recording transducer 10 functions, there are drawbacks. In particular, the conventional magnetic recording transducer 10 may not function adequately at higher recording densities. Two-dimensional magnetic recording (TDMR) technology may enable significantly higher recording densities. In TDMR, multiple read sensors are used. These sensors are longitudinally distributed along the cross track direction. The central sensor reads the data from a track of interest, while the outer sensors sense the data in adjacent tracks in order to account for noise.
Although TDMR might be capable of higher recording densities, issues may complicate fabrication of a read transducer or adversely affect its performance. Fabrication of an additional read sensor above the read sensor 14 shown, in place of the shield 20, may be complicated. Such a read sensor would be desired to be electrically isolated from the read sensor 14. However, the conventional electric gaps 22 do not allow for a flat topology. If the electric gaps are omitted, electrical insulation may be insufficient. If the additional read sensor is fabricated above the tops of the electric gaps 22, too large a space may be between the read sensors. Consequently, a transducer suitable for use in TDMR and which may be relatively simply fabricated is desired.